基于物理机制的工程场地地震动相干函数模型

The coherence function model of ground motion in engineering sites based on physical mechanism

基于工程场地地震动随机场的物理模型,本文提出了基于物理机制的工程场地地震动相干函数分析模型,利用概率密度演化方法(PDEM),可以求解工程场地的地震动相干函数.通过与经验相干函数模型Harichandran-Vanmarcke模型和Hao模型的对比,验证了这一模型的合理性.随后,利用该模型研究了4类不同工程场地相干函数特征,并分析了不均匀分布复杂场地的相干函数.相比于传统的经验或者半经验的相干函数模型,本文模型为理解地震动场相干特性提供了新视角,即根据各种不同物理因素和地震波传播的物理机制确定地震动场的相干性,为分析和确定工程场地地震动场的相干性提供了一类新方法.

Based on the random physical model of seismic ground motion field on local engineering site, this paper suggests a theoretical coherence function model of ground motion in engineering sites based on physical mechanism; probability density evolution method（PDEM） is used to solve this theoretical model. The comparison between the theoretical model and the Harichandran-Vanmarcke model as well as Hao model has proved the rationality of the suggested model. Then the model is used to study the characteristics of the coherence function in four kinds of seismic engineering sites and the non-uniform sites in lateral direction. When compared with the traditional empirical or semi empirical models, the model suggested in this paper provides a new perspective to understand the coherence in earthquake field, which means to determine the earthquake field coherence based on different kinds of physical factors and the physical mechanism of seismic wave propagation. This can be a new method to analyze and determine the earthquake field coherence.